As an inspiring and latest guidance for research concerning
smart world, this paper has discussed various technologies
and issues with respect to green IoT, which plays a significant
role in achieving a sustainable smart world. Specifically, the
overview regarding IoT and green IoT has been performed.
The technologies related to green IoT including five hot
green ICT (e.g., green RFID, green WSN, green CC, green
M2M, green DC) have been introduced, with the summary of
general green ICT principles. In addition, bestowing particular
attention to sensor-cloud which is a novel paradigm in
green IoT, the latest developments about sensor-cloud have
been shown and the future sensor-cloud has been envisioned.
Finally, future research directions and open problems regarding
green IoT have been presented.